Burgessite is a rare cobalt arsenate mineral known primarily from its type locality in Ontario. It forms delicate, pale pink prismatic crystals that are visually similar to erythrite but distinct in crystal structure and composition.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Burgessite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this burgessite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch burgessite with a known reference. Burgessite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Burgessite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Burgessite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: pink, pale pink.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

Burgessite vs. its common look-alikes — and how to tell them apart in the field.

mineral

Erythrite

Mohs 1.5-2.5

How to tell apart: Streak differs — Burgessite leaves white, Erythrite leaves pale pink; luster reads vitreous on Burgessite and adamantine to pearly on Erythrite.

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Often found alongside burgessite

Minerals reported to co-occur with burgessite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Co₂(AsO₄)(OH)·8H₂O
Mohs hardness: 2
Density: 2.25 g/cm³
Colors: Pink Pale Pink
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Cobalt-silver Veins
Typical price: $50-300 per specimen depending on size and quality

Where rockhounds find burgessite

Classic worldwide localities

Burgess mine, Ontario, Canada

Field-hunting tip

Look in hydrothermal cobalt-silver veins country — that is the host setting where burgessite typically forms. If you start seeing erythrite, cobaltite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify burgessite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include pink, pale pink.

Where is burgessite found?+

Notable localities include Burgess mine, Ontario, Canada.

How much is burgessite worth?+

Typical asking prices fall in the range of $50-300 per specimen depending on size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is burgessite safe to handle?+

It contains toxic constituents. Contains arsenic and cobalt; wash hands thoroughly after handling and avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like burgessite?+

Burgessite is most often confused with Erythrite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with burgessite?+

Burgessite commonly co-occurs with erythrite, cobaltite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does burgessite form in?+

Burgessite typically forms in hydrothermal cobalt-silver veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is burgessite used for?+

Burgessite is used in collector.

Find burgessite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.